Sheet feeder



Dec. 15, 1936. w. R. HOTCHKISS SHEET FEEDER Filed June 24, 1953 2Sheets-Sheet 1 Dec. 15, 1936 w R HOTCHK|$$ 2,064,004

SHEET FEEDER Filed June 24, 1933 2 Sheets-Sheet 2 Patented Dec. 15, 1936UNITED STATES Z,tt4,004

PATENT OFFEE SHEET FEEDER William Roy Hotchkiss, St. Paul, Minn.

Application June 24, 1933, Serial No. 677,479

8 Claims. (01. 27153) My invention relates to sheet feeding means whichmay be applied to a printing press, however, the principles andstructure thereof may be equally applicable to other devices where it isdesirable to feed sheets in the same manner. I have illustrated thesheet feeder associated with a lithographing cylinder and theaccompanying parts to define the principles of the means whichaccomplish the desired results.

A feature resides in providing a sheet feeding means which is associatedwith sheet carrying means, stops, and gauge means, so that the sheet maybe positioned to give an accurate registration as the sheet is carriedfrom the feeding table to the lithographing cylinder.

In lithographing machines using a rotary cylinder, gripper fingers areprovided which are carried by the cylinder and rotate with the same.These fingers grip the edge of the sheet fed to the cylinder, and owingto the fact that the rotary motion of the cylinder is comparativelyrapid and is continuous, it is possible in transferring the sheet fromthe feeding bed to the cylinder, that the sheet may slip slightly andget out of registry, preventing an accurately adefined impression andmaking it diificult to make a perfect registration of the sheets, eventhough the sheet has been definitely and perfectly registered on thetable. The sheets are usually carried from the stack by feeding meansonto a table which has a conveyor adapted to carry the sheets up to theimpression cylinder. The sheets are accurately registered on the tableprior to being fed to the gripping fingers of the cylinder, and it isessential that this registry be maintained on the cylinder to give anaccurate impression or printing of the sheets. I accomplish this byproviding the necessary means for registering the sheets on the registrytable and for carrying the sheets therefrom into accurate and positiveregistration on the impression cylinder, preventing any possibleslipping of the sheet out of registry before it is positively engaged bythe gripping fingers of the impression cylinder.

It is also a feature to provide means for engaging the registered sheetand over-feeding it to stops adjacent the engaging ends of the grippingfingers, so that the sheet is actually fed against the registering stopsassociated with the gripping fingers of the cylinder and not just pickedup by the fingers and carried onto the impression cylinder. My over-feedmeans has an outstanding advantage of insuring the holding of the sheetinto registry and forcing it into position, whereby it is positivelyengaged by the gripping fingers uniformly and in accurate registeredposition so that there is no chance of the sheet getting out of registrybetween the table and cylinder. My over-feed means drives the 5 sheetwith a little more extra force or speed than would be necessary to justtime the movement of the sheet with the movement of the gripping fingersof the impression cylinder, thus causing the sheet to bow slightlyadjacent the over- 10 feeders as the edge of the sheet strikes the stopsat the gripping fingers and then the over-feed means does not releasethe sheet until after the gripping fingers have positively engaged thesame, whereupon the over-feed is released and is inoperative until it istime to engage the next sheet in the same manner.

It is also a feature to provide guide means extending around thecylinder with slots through which the edges of the gripping fingers maypass while they are in their open position projecting from the cylinder.This guide means holds the forward edge of the sheet so as to bring thesame into perfect alignment with the stops adjacent the gripping fingerson the cylinder.

I also provide means for preventing any backlashing in the over-feedmeans so that a positive and accurate registration is obtained with myrotary over-feeding means and the rotating impression cylinder.

In the drawings forming part of this specification:

Figure 1 is a diagrammatic plan View of a portion of a lithographingpress, illustrating the sheet registry table and showing my overfeedingmeans associated therewith to feed the sheets to the cylinder of thepress.

Figure 2 is a diagrammatic side view of the left-hand side of the same.

Figure 3 is a detail portion of the same.

Figure 4 is a small sectional view through the impression cylinder,showing the gripper cam in dotted outline, and arm for operating thegripping fingers by the cam.

Figure 5 is an enlarged diagrammatic sectional detail on the line 55 ofFigure 1.

Figure 6 is a diagrammatic section of a portion of the associated partssimilar to the section of Figure 5, showing the over-feeding of thesheet to the impression cylinder.

Figure '7 is a diagrammatic detail of the Genneva feeding means.

Figure 8 is a detail showing the brake on the shaft operating theover-feeding rolls to overcome back-lashing.

The press A which is provided with the impression cylinder B is onlypartially illustrated to show the associated parts with which my sheetfeeder C operates. The press A is provided with a sheet feeding andregistering table In. Conveyors H operate in the bed of the table Ii].These conveyors incline toward the longitudinal feed gauge D and carrythe sheet in the direction of the arrow in Figure 1, along the table Itunder the balls 12 which are carried in the outer ends of the adjustablebrackets 13 which are positioned above the conveyors H so that the ballsl2 will tend to hold the sheets bearing against the conveyors H. Thesheets E are carried onto the table ID by any suitable sheet feedingmeans which operates intermittently to feed the sheets onto the tableand to the conveyors H and which is not shown in the drawings.

My sheet feeder C is formed with over-feeding wheels 14 which may berubber-faced, or of any suitable material, so as to readily engage thesheets E at the proper time to feed them in the manner as will bepointed out. The wheels l4 are carried upon the shaft [5 which is heldby the brackets it to the transverse shaft H. The ends of the; shaft l!are mounted to the frame of the press A. The brackets 6 hold the shaftI5 so that the wheels Hi may be raised and lowered intermittently. Theshaft I7 is limited in turning to move the wheels l4 down toward theunder wheels E 3 by an adjustable bracket 18 which carries an adjustingscrew IS in the free end of the same, acting as a stop to prevent theshaft i'z' turning beyond the limits of the setting of the stop screwi9, and thus regulating the downward movement of the wheels it towardthe under wheels I l. The under wheels M are mounted on the shaft 60 ofthe mechanism F. The under wheels M are directly below the wheels M andco-operate therewith to feed the sheets in the feeder C.

The sheet feeder C is provided with a sheet guiding plate 20 whichextends above the table It! to form the sheet guiding space 2! betweenthe table i8 and the plate 26, and the forward end 22 of the plateextends closely thereto so as to guide the forward edge of the sheet E.A recess 23 adjacent the wheels M is formed in the under surface of theplate 23 so as to permit the sheets E to raise slightly when they areover-fed to the cylinder B.

The forward edge of the sheet E is caused to engage stop pins 24 carriedby the shaft 25 when the sheet E is brought into registry upon the tableIf). These pins project toward the table Ill and act to register thefront edge of the sheet and to stop the sheet from forward movement onthe table in while it is being registered. The shaft 25 rotates to carrythe pins into the position illustrated in Figures 5 and 6 after thesheet has been registered on the table It and when the over-feeder Coperates to feed the sheet E to the gripping fingers 26 of the cylinderB.

Adjacent the shaft 25 and the pins 24, I provide a fixed sheet guide 27which has a sheet guiding skirt 28 which curves around the shaft 25 andis slotted to permit the pins 24 to rotate into and out of sheetstopping position. The pins 24 rotate out of stopping position in thedirection of travel of the sheet E. The guide 21 has an arcuated undersurface 29 which fits closely to the end of the table [0 over which itlies and over the cylinder 13, as illustrated in Figures 5 and 6. Thisarcuated surface 29 provides a guide for the forward end of the sheet Eas it is driven by the over-feed wheels 14 to the gripping fingers 25.The guide 2'1 is formed with arcuated slots 30 cut into the arcuatedsurface 29 which permits the free gripping ends 26' of the fingers 26 topass through the same while in open position. As the impression cylinderB rotates, carrying the fingers into the slots 30, the fingers 26 areopened and while in these slots the forward edge of the sheet which hasbeen registered against the pins 24, is driven from this position by theoverfeeder wheels I4 and the under feeder wheels [4' against the stops3!. The fingers 26 then close down onto the edge of the sheet E beforethe fingers are out of the slots 30 and while the edge of the sheet isheld under the arcuated guidance surface 29. The guide 21 provides ameans of holding the forward edge of the sheet E so that it may bedriven against the stops 3| and under the ends 26 with sufiicient forceto insure registry of the sheet E on the cylinder B. While the sheet isdriven up in this manner it is held firmly by the engagement of thewheels M and It. Thus the sheet cannot possibly skew-gee or slip out ofregistry and is therefore carried to the impression cylinder B inperfect registry.

The over-feeding sheet means C is operated by the lever 32, one end ofwhich is secured to the shaft I? and the other end is urged by thespring 33 to tend to rotate the shaft H in a manner to cause the arm Itto bear down on the shaft [5 and in turn move the wheels 14 toward thetable 50. However, the cam arm 34, one end of which is secured to theshaft l1, and the other end of which engages the intermittent motion cam35, normally holds the over-feed wheels I l out of operative position toengage the sheet E coming along in registering position on the table IIThe shaft i5 is connected by the gear 36 to the driving gear 31 whichoperates on the shaft 38, and the gear 31 is adapted to beintermittently operated by the Geneva mechanism F. The Geneva mechanismis of the usual form with the intermittent motion wheel 39 and theGeneva drive wheel 40, illustrated in Figure '7. The drive wheel 40 isdriven by the shaft 4| of the press A in any suitable manner, notillustrated.

The Geneva mechanism F is intermittently operated to rotate theover-drive feeding wheels H5 and the wheels I l after the sheet E hasbeen registered on the table ID with its forward edge stopped againstthe pins 24. Then the intermittent motion cam operates to drop thewheels l4 into engagement with the sheet E to firmly engage and hold thesheet against moving out of registry, after which the pins 24 arerotated by the lever means 42 which is lifted by the cam roller 43traveling upon the stop cam 44, and subsequent to this operation theGeneva mechanism F starts to rotate the wheels [4 and I4 through thegears 35 and 37. The rotation of the over-drive wheels l4 and theunder-drive wheels Hi forces the sheet E against the stops 3!, ashereinbefore set forth, while the ends 26 are in open position in theslots 30. The wheels i4 and I4 operate fast enough to provide a slightlygreater impulse to the sheet E than would be necessary to bring it intodirect time with the movement of the cylinder B. The front end of thesheet E is held under the guide 21 so that it cannot buckle or twist.The over-driving of the wheels i l and. I4 causes the sheet to bulge upslightly into the recess 23 of the guide 25, and the fingers 26positively grip the front end of the sheet E, securing it in perfectregistry to the cylinder B, after which the cam 35 raises the arm 34,which in turn raises the wheels l4, and the Geneva mechanism stops therotation thereof.

The gears 35 and 31 do not disengage but are moved. slightly apart outof their pitch engagement. To maintain the shaft l5 in perfect registryoperation, I provide an adjustable brake 45 which is formed with anadjusting screw 6 and gripping shoes 47 to adjust the tension on theshaft [5 and thereby overcome any backlashing and preventing any changein the registering operation of the mechanism C.

The degree of pressure of the wheels against the sheet E is regulated bythe stop [3 so that more or less engagement may be provided, accordingto the adjustment of the screw 99.

When the sheet E is engaged by the grippers 26, it is carried around thecylinder B in accurate registration thereon. There has been no chancefor the sheet to slip or lag and, therefore, it is in positiveregistration. The sheet E is released from the grippers 25 at the propertime when the shoe fly levers 48 operate to cause the ejecting pins 49to release the sheet from the ends 26.

It will therefore be apparent that I provide a means of feeding sheetsto the impression cylinder B, maintaining them in perfect registry atall times and preventing any possible chance of the sheets lagging inrelation to the impression cylinder B in the movement thereof, eventhough the condition of the paper may vary, owing to the atmosphericconditions. Thus the sheet cannot slip out of registry in beingtransferred from the feeding table to the impression cylinder. Thewheels M and i l give two distinct points of engagement to more securelyhold the sheet. It is also evident that my feeding means may be appliedto other devices where a feeder of this character is desired, other thanpresses, while the essential accomplishments in relation to alithographing press evidence the outstanding merit of the same.

The illustrations are only suggestive of a means of carrying out theprinciples of the invention which should be considered within the scopeof the claims to provide the broadest interpretation thereof.

I claim:

1. A sheet booster for printing presses including, a series of resilienttired Wheels, means for holding said wheels inoperative, preliminaryside and front sheet registering means associated with said wheels, aGeneva mechanism for intermittently operating said wheels, a gear backlash preventing brake therein, means for causing said wheels to engagethe sheet before rotation of the same, and means for releasing thewheels fromthe sheet after it has been boosted by said wheels intoprinting position.

2. A sheet engaging and feeding means for rotary printing pressesincluding, resiliently tired sheet engaging wheels, means for normallyholding said wheels out of engagement with the sheet while it isregistered, means providing a preliminary side and front registry forthe sheet, means for moving said wheels into engagement with the sheetafter it is registered and while said wheels are not rotating, meansreleasing said sheet registering means, a Geneva operated means forrotating said wheels to drive the sheet to registering position on theprinting cylinder, a gear back lash preventing brake therein, and sheetguiding means associated with the cylinder and the grippers thereof toguide the forward end of the sheet into registering position so as to beengaged by the grippers while the body of the sheet is fed, with. ahigher speed to over-feed the same to the gripping means of thecylinder, and means for releasing said driving wheels when the cylinder"ipping fingers have positively engaged the same.

3. A sheet feeding device including, a rotatable lithographing cylinder,grippers on said cylinder, and means for over-feeding a sheet to saidgrippers including, a registering stop, a pair of cylindrical rollersengageable with the sheet registered by said stop, and means forrotating said rollers with a gradually increasing and. decreasing speed,said rotation being started before said stops are released for feedingsaid sheet to said grippers including a pair of discs, a pin on onerotatable disc engageable in slots in the other disc to impartintermittent motion thereto, and means cooperating between the discs tohold said other disc motionless between engagements, means for releasingsaid stop upon engagement of the sheet by said rollers, and means forholding said rollers against said sheet until said sheet is engaged bysaid grippers.

4. A sheet feeding device comprising, a rotatable cylinder, means forfeeding sheets to said cylinder including, a pair of rollers spacedapart, registering stops, means releasing said stops after movement ofsaid rollers has started, means for moving said rollers together intocontact with opposite sides of a sheet, means for rotating said rollerswith a gradually increasing and gradually decreasing speed including apair of discs, one of said discs being rotatable, a pin on said onedisc, grooves on the other disc cooperable with said pin to rotate saidother disc intermittently, and means cooperable with said discs to holdsaid other disc from rotation between intermittent movements thereof,and means for spacing said rollers after said sheet has been received bysaid cylinder.

5. A sheet feeding means including, a rotary cylinder, grippers thereon,and a mechanism for feeding sheets thereto including, a cylindricallower sheet engaging roller, a rockably mounted cylindrical upper sheetengaging roller cooperable with said lower roller to engage a sheettherebetween, registering stops, means releasing said stops after saidrollers start in motion, a cam for rocking said upper roller into andout of engaging position, said cam moving said upper roller out ofengagement with said sheet after said sheet is engaged by said grippers,and means for intermittently operating said rollers in unison.

6. A sheet feeding device including a feeding table, a pair of spacedfeeding members for feeding a sheet on said table, means for moving saidfeeding members together to engage a sheet, stop means for holding saidsheets in registered position, a longitudinally extending fixed guidemember suspended above said table, an end on said guide member extendingadjacent said stop means and slightly spaced from said table to guidesaid sheets against said table adjacent said stop, and a cut awayportion in said guide hers to accommodate a bulge in the fed sheetbetween the stop means and the feeding means.

7. A sheet feeding device comprising stop means for registering a sheet,relatively movably mounted pairs of feed rollers, means for moving saidrollers of each pair together to engage a sheet, means .for rotatingsaid rollers, and means for releasing said stop means after 10 movementof said sheet by said feed rollers has started.

' member between-said end and said feeding mem- WILLIAM ROY HOTCHKISS.

